A souterrain, the term for an underground stone-lined passage or room typically built in early medieval Ireland for storage or refuge, once sat at the centre of the enclosure here. It has since been filled in, and the ground above it gives nothing away.

The record of this place is thin by necessity. In 1939, the archaeologist P. J. Hartnett was told by local people that the souterrain had consisted of a single chamber, its walls lined with stone and its roof formed from large flat lintels laid across the top. By the time that account was collected, it had already been infilled. Whether this happened deliberately, through agricultural convenience, or simply through neglect over many decades is not recorded. What remains is the ringfort itself, a circular earthwork enclosure of the kind commonly associated with early medieval farming settlements in Ireland, and the knowledge that something once lay hidden at its centre.